Piggy-back carton stacker



A. J. TONNA 2,934,221

PIGGY-BACK CARTON STACKER April 26, 1960 Filed April 23, 1958 3Sheets-Sheet 1 INVENTOR. ARTHUR J TON/VA ATTORNEYS April 26, 1960 A. J.TONNA 2,934,221

PIGGY-BACK CARTON STACKER Filed April 23, 1958 3 Sheets-Sheet 3INVENTOR. ARTHUR J TO/VNA A T TORNE VS United. States Patent PIGGY-BACKCARTON STACKER Arthur Tonna, San Francisco, Calif., assignor toBurgermelster Brewing Corporation, San Francisco, Calif., a corporationof California Application April 23, 1958, Serial No. 730,470

2 Claims. (Cl. 214-6) This invention relates to carton stackers and moreparticularly to a stacker which is adapted for automatic stacking ofcartons atop one another in predetermined numbers.

It is an object of this invention to provide a machine adapted forproduction line use which will automatically stack cartons inpredetermined numbers atop one another in piggy back fashion at highspeed.

It is another object of this invention to provide a machine of thecharacter described, the normal operation of which will not be affectedby substantial variations in the rate of carton feed to the machine.

Still another object of this invention is to provide a machine of thecharacter described which may be readily adapted to receive cartons ofvarious shapes and sizes, singularly or in multiples.

Other objects and advantages of this invention will become apparent fromthe following description taken in conjunction with the drawings formingpart of the specification in which:

Figure l is a view in side elevation partially broken away of themachine of this invention illustrating the direction of carton flowtherethrough.

Figure 2 is a sectional view taken along the line 2-2 of Figure 1 withcartons undergoing upset being shown in phantom outline.

Figure 3 is a fragmentary view in plan of the machine.

Figure 4 is a view in section taken along the line 4-4 in Figure 1.

Figures 5, 6, 7 and 8 are simplified views in side elevation showing, inorder, the sequence of operations of the machine of this invention.

Figure 9 is an across-the-line wiring diagram illustrating a preferredmethod of control for the machine of this invention.

Referring now to the drawings, there is provided a supporting frameworkhaving a horizontal bed 12 comprising an inverted channel member 14carried upon uprights 16 and 18. A ram 22 is disposed for reciprocationin a horizontal planeabove the surface 24 of bed 12 being connected by arod 26 to ram actuating means comprising a piston 28 and a cylinder 30,the latter secured to bed 12 by means of studs 32. Hydraulic lines 34and 36 are provided to communicate with either end of the cylinder 30,and solenoid control valves 38 and 40 (Figure 9) are provided forcontrolling the flow of fluid through these lines to such cylinder. Areversible limit switch 42 having a plunger 44 is secured to bed 12 atone side of cylinder 30 by means of studs 46. Secured to the other sideof cylinder 30 is a similarly reversible limit switch 48 having aplunger 50.

The ram 22 is comprised of a web member 52 with shaped flange members 54and 56 secured perpendicular to and depending from either side of theweb member. A rectangular face plate 58 is secured intermediate flanges54 and 56 and the web member 52 in perpendicular relationship thereto.The connecting rod 26 is secured perpendicular to the rear side of theface plate 58 and serves to carry the ram 22 in its reciprocal movementabove bed 12. A pair of elongated rods 60 and 62, respectively securedto flanges 54 and 56, extend rearwardly beneath web member 52,paralleling connecting rod 26. Rod 62 is provided with a right angleprojection 64 for effecting reversal of the contacts of the limit switch48 by engaging the plunger 50 thereof when the ram 22 reaches itsextended position indicated in phantom outline in Figure 4. Rod 60 isaligned to engage the plunger 44 of the limit switch 42, in effectingreversal of the contacts of such switch upon ram retraction.

A carton carrying elevator 66 is disposed for vertical reciprocalmovement adjacent the ram 22 and is comprised of a pair of partiallytapered spaced-apart parallel plates 68 secured to uprightsemi-cylindrical members 70, which latter are secured to cross members72 at either end thereof. The parallel plates 68 of elevator 66 arespaced apart a distance sufiicient to permit reciprocation therebetweenof the ram 22 without physical interference with the up and downmovement of the elevator 66; and a pair of parallel rectangular slots 74are provided in bed 12 to permit reciprocation therethrough of theelevator plates 68. The elevator 66 is carried in its reciprocalmovement upon the upper end of rod 76 which is secured perpendicular toand intermediate the ends of cross member 72. Elevator 66 is actuated bymeans comprising a piston 78 reciprocating in a cylinder 80 which lattercommunicates at either end with hydraulic lines 82 and 84 and is securedto horizontal framework member 86 in an upright position by means ofstuds 88. Solenoid control valves 90 and 92 (Figure 9) are provided forcontrolling the flow of fluid through lines 82 and 84 to and from thecylinder 80.

Fastened to an upright framework member 18, slightly above and to oneside of the elevator actuating means, is a normally open limit switch 94having pivotally connected thereto a link 96 which is positioned toeffect the closure of the contacts of the limit switch by engagingelevator cross member 72 at the lower portion of the elevators strokethrough roller 98 rotatably secured to the free end of the link. Asimilar normally open limit switch 100 is mounted upon the underside ofbed 12 adjacent the path of travel of elevator cross member 72. Thecontacts of switch 100 are closed as the elevator 66 reaches the upperportion of its stroke through the action of a pivotally mounted link 102which engages the elevator cross member 72 through roller 104 rotatablysecured to the free end of the link.

A stacked-carton conveyor 106, comprising an endless belt 108 trained atone end about idler roller 110 and passing through slot 112 inhorizontal bed 12, is disposed adjacent the elevator 66 to be driven inrotation by means (not shown) in a direction from left to right asindicated in Figure 1. The conveyor 106 has a cartoncarrying upper reach114 substantially co-planar with the upper carton-supporting surface 24of bed 12, and is aligned with the ram22 in its path of reciprocatingtravel. An inverted channel member 116 serves to support the conveyorbelt 108 which moves upon the upper surface.

118 of the web 120 thereof. Roller 110 is fixedly secured to shaft 122journalled in bushings 124 and 126. Bushing 124 is secured to flange 128of channel member 116 and bushing 126 is secured to upright member 130,in turn secured to flange 132 of channel member 116. Guide rails 134positioned horizontally at either side of the conveyor 116 are supportedby upright members 136 secured to flanges 128 and 132 of channel member116.

Positioned above the bed 12 in alignment with the path of up and downreciprocating movement of the elevator 66, is a carton-receiving hopper138 which is comprised of horizontally disposed rails 140 and 142, whichat their inner or rearward ends are secured to upright framework member144 and extend perpendicularly outward therefrom, being at their outerends bent at right angles toward each other and respectively secured tocentral upright members 146 and 148. Rail 140 is further securedintermediate its extremities to curved upright member 150, and rail 142is secured to upright member 152 and curved upright member 154. Centralupright members 146 and 148' are secured at their lower ends to bed 12and curve outwardly at their upper ends to facilitate receipt of cartonsby the hopper 138. Upright member 150, offset outwardly at its upperend, is at its lower end secured to bed 12 and, as shown in Figure 2,curves backwardly at its upper end, being secured thereat to horizontalguide rail 156. Upright member 154 is secured to bracket 158, whichlatter is secured at its inner end to member 144. Member 154 ispositioned opposite member 150. and, like the latter, is offsetoutwardly at its upper end. Upright member 154 is likewise backwardlycurved at its upper end and, is secured thereat to horizontal guide rail160. Also secured to bracket 158 is the member 152 which extendsupwardly therefrom, being secured at its upper extremity to member 154and being provided with an outward offset at its upper end similar tothose of members 150 and 154. The members 150, 152 and 154, olfset attheir upper ends and disposed about the hopper 138, define an enlargedupper entry or mouth for such hoppen.

Photoelectric control means comprising a photocell 162 and a lightsource 164, respectively secured to framework members 144 and 166, arepositioned adjacent the hopper 138 such that the path travelled by thelight beam emitted by light source 164 in reaching photocell 162-traverses the hopper 138. The photoelectric control. means, whichprovides the machine with a self-control. feature, acts through a timedelay relay 168 in controlling the machine operation.

A feed conveyor 170 is disposed adjacent the upper end of the hopper138, the chain 172 of the conveyor being trained around sprocket 174 tobe driven thereby. Sprocket 174 is secured to shaft 176 journalled inbushings 178 and 180, respectively, which latter are secured to uprightmembers 166 and 130. Sprocket 182, and the shaft 176 to which it isfixedly secured, are driven in rotation by chain 184, trained aroundsprocket 182,

and in turn drive in rotation sprocket 1.74 and conveyor chain 172trained thereabout. Segments 186, preferably of rubber or of a materialwith similar gripping characteristics, are bonded to alternate links ofchain 172 throughout its length to facilitate the carrying of cartonsthereon. The chain 172 is guided in its rotation by a narrow channelmember 188 secured to upright member 130 through use of brackets 190 and192. Positioned at either side of the feed conveyor 170 are upright members 194 and 196 secured to brackets 190 and 192, and respectivelycarrying pairs of horizontally disposed guide rails 156 and 198, and 160and 200. The rail 160 near its right end (Figure 1) is provided with aninwardly extending offset 202.

In operation, upright cartons 204 and 206, with cans 208 similarlyupright therein, are fed by conveyor 170 from left to right in Figure 1,being maintained in upright condition by the horizontal guide rails 156,198, 160 and 200 until reaching a position approximately that of carton206. Here the upper forward portion of the carton is engaged by theofltset 202 of'rail 160, which exerts an upsetting moment upon thecarton cau's-' ing it to tumble from its upright position. upon feedconveyor 170 to a position upon its side in thehopper 138. The upsettingof the carton is facilitated'by the limited support offered thereto bythe chain 172 and the channel 188. The position which such upset carton"will assume in the hopper will of course depend upon the number ofcartons stacked therein at the time.

7 The car ton may thus fall to the surface 24 of the'bed 12, or atopanother carton. However, in the course of normal operation, the cartonwill drop from the conveyor upon its side atop other stacked cartons,rather than directly upon bed 12 because of the sequence of operation ofthe elevator 66 and ram 22 as described hereinafter. In falling into thehopper 138 the carton breaks the beam of the photoelectric control meansmomentarily, or for a substantial period of time, depending upon theposition which it ultimately assumes in the; carton stack. With thephotoelectric control means positioned as shown in Figure 1, the lightbeam thereof is broken for a substantial period of time only by a fourthcarton such as 210, side-stacked piggy-back atop three others in thehopper 138. Any carton falling to a position therebelow such as that ofcarton 212, effects only momentary interruption of the beam. From thedescription of the machine operation set forth hereinafter, it will beappreciated that such a position for the photoelectric control means isessential to assure that the machine will operate at all times to effectthe stacking of cartons in pairs, with automatic machine shut-otf,should two stacked cartons not be available for positioning by theelevator adjacent the ram.

Toprevent momentary energizing and de-energizing of the control systemas a result of momentary interruption of the beam of the photoelectriccontrol means, the relay 168 (Figure 9), incorporating a time delayfeature, is provided. The-solenoid 168a of the time delay relay 168 isconnected in series with the photocell 162 and is energized to break thecircuit through such relay by holding the moving contact 168b of therelayopen when the beam of the photoelectric control means ismaintained. As shown inFigure-9, this relay at one terminal is connecteddirectly to electrical line L1 and at the other terminal is seriesconnected to parallel. circuits comprised'of ram-and elevator actuatingvalves and associatedlimit switches, and thus said relay controls theenergizing of the control system in response to the photoelectriccontrol means.

For the purpose of describing the sequence of machine operation, thecondition of Figure 5 is initially assumed with three cartons stackedatop one another upon surface 24 of bed 12, the elevator 66 being inretracted position slightly below the surface 24 of bed 12 and the ram22 being retracted to the far. left. In this condition, limit switch .94is closed and limit switch 48 is positioned to effect series connectionof the control solenoid 38a for. ram actuating valve .38 with time.delay relay 168 and electrical line L2. The control solenoid 92aofelevator actuating valve 92 is series connected with time delay. relay168 through limit switch 42. Limit switch 100, which is connected inseries with the control solenoid 40a of ram actuating valve 40, is open.The positions'of limit switches 42 and 94, it may be noted, are thereverse of the normal positions for these switches shown in Figure 9.

With the stacking of a fourth carton 210 atop three others, as shown inFigure 6, the beam of the photoelectric control means is broken,effecting closure of the movable contact 168b of time delay relay 168 byde-energizing the relay solenoid 168a. The control solenoid 38a forram-actuating valve 38 is thereby energized, causing the valve 38 toeffect connection of line 34 to a pressurized hydraulic fluid supplyline (not shown) and connection of line' 36 to a return line (notshown). Fluid flowing into cylinder 30 through line 34 causes piston 28and ram 22 connected thereto to extend-to the right. The ram'22 engagesthe lower pair of piggy-back-stacked cartons 214 and 216, with its faceplate 58 squarely abutting the aft ends thereof. The cartonsarethereupon moved by ram "22 to the right, as indicated in Figure 6, topass over the retractedelevator 66 and the slots 74 therefor as may bestacked above, from moving with the lower pair of cartons 214 and 216,in effect permitting the ram 22 to shear such lower pair of cartons fromcartons stacked above in the hopper 138. The web member 52 of the ram 22is disposed to clear bracket 158 and the lower surface ofthe thirdstacked carton 212, permitting ram 22 to move cartons 214 and 216 to theright beneath carton 212. The web member 52, however, maintains thecartons 210 and 212 in elevated position as the ram moves the pair ofstacked cartons to the right. This prevents the top carton 210 fromdropping from its beaminterrupting position of Figure 6 with aconsequent breaking of the valve control circuits through the actuationof the time delay relay 168. Only after moving, relatively, to aposition approximately midway of the length of cartons 214 and 216, doesthe third carton 212 contact the upper surface of the ram web member 52,tilting downwardly thereon, eventually to be substantially supported bysuch. member as shown in Figure 6. As the pair of piggy-back-stackedcartons 214 and 216 .move past the right-hand edge of slot 112 of bed12, they are engaged by the stacked-carton conveyor 106 which operateswith its carton-carrying upper reach 114 moving from left to right(Figure 6). The piggy-back-stacked cartons are thereupon carried by theconveyor down the line for packing, as by a tray packer (not shown) orfor other disposition.

As the ram 22 approaches its fully extended position, having pushedcartons 214 and 216 substantially past the right-hand edge of slot 112,the projection 64 of rod 62 engages plunger 50 of limit switch 48. Limitswitch 48 is caused thereby to reverse its position, effecting closureof valve 38 to the flow of fluid therethrough from hydraulic lines 34and 36 by deenergizing the control solenoid 38a for the ram actuatingvalve 38 by way of breaking its connection with electrical line L2.Limit switch 48 at the same time energizes the control solenoid 90a forelevator actuating valve 90, connecting it with electrical line L2. Withthe energizing of the control solenoid 90a, valve 90 connects hydraulicline 84 to a pressurized hydraulic fluid supply line (not shown) andhydraulic line 82 to a return line (not shown). Hydraulic fluid isthereby admitted through line 84 to cylinder 80 causing the piston 78and the elevator connected thereto to move upward, the plates 68 ofelevator 66 moving through the slots 74 in bed 12 to engage theunderside of carton 212. The cartons 210 and 212 are thereby maintainedby elevator 66 in an elevated position clear of ram 22 as the latterretracts, as explained below, between the plates 68 of the elevator 66.

With the raising of elevator 66 to the extended position, closure oflimit switch 100 is effected through engagement of link 102 and itsroller 104 with elevator cross member 72. This energizes the controlsolenoid 40a of ram actuating valve 40, the limit switch 42 efiectingconnection between the control solenoid 40a and the time delay relay 168when the ram 22 is in a non-retracted position. With energizing of thecontrol solenoid 4042, the ram actuating valve 40 effects connection ofhydraulic line 36 to a pressurized hydraulic fluid supply line (notshown) and connection of hydraulic line. 34 to a return line (notshown), resulting in the admission of fluid to cylinder 30 through line36. The piston 28 and the ram 22 connected thereto are forced to retractto the left as shown in Figures 7 and 8 between the upraised plates 68of elevator 66 and beneath the cartons 210 and 212 maintained inelevated position by the elevator 66. With the start of retraction ofram 22, the limit switch 48 is caused to reassume its normal positioneffecting closure of valve 90 to the fluid flow of hydraulic lines 82and 84 by de-energizing the control solenoid 90a through disconnectionthereof from electrical line L2. As the ram 22 approaches its fullyretracted position, rod 60 is caused to engage the plunger 44 of limitswitch 42, effecting reversal of the switch and the de-energizing of thecontrol solenoid 40a for the'ram actuating valve 40 by breaking theconnection thereof to time delay relay 168. With deenergizing of itscontrol solenoid 40a, the valve 40 is closed to the flow of fluid thoughhydraulic lines 34 and 36. Limit switch 42 at the same time effects theenergizing of the control solenoid 92a for elevator actuating valve 92by connection thereof to time delay relay 168. With energizing of thecontrol solenoid 92a, valve 92 effects connection of line 82 to apressurized hydraulic fluid supply line (not shown) and connection ofline 84 to a return line (not shown), resulting in admission of fluid tocylinder to move piston 78 and elevator 66, connected thereto, downward.The cartons 210 and 212 carried by elevator 66 are thereby lowered ontothe surface 24 of bed 12 adjacent ram 22 to the right, ready for thestart of another cycle.

It will be observed in Figure 8 that the carton 206 and others followingit into the hopper, maintain interruption of the beam of thephotoelectric control means as the elevator lowers the cartons 210 and212 to bed 12. This of course prevents stoppage of the machine whichwould otherwise occur were the beam of the photoelectric control meansnot so interrupted.

It will be appreciated that the embodiment of this invention describedabove may be altered, changed or modified without departing from thespirit or scope of the invention as herein claimed. Thus, the machinemay easily be-adapted to stack cartons in various numbers atop oneanother by varying the elevation of the photoelectric control meansrelative to the hopper and by changing the dimensions of the ram andelevator and the clearances for the reciprocating travel thereof.Provision may similarly be made for handling cartons of various shapesand sizes. Further, this invention is not necessarily limited to amachine for receiving single cartons in upright condition to beindividually side-stacked piggyback fashion, but is equally useful forreceiving cartons in various multiples and dispositions to be stackedatop one another in units of two or more.

What is claimed is:

1. A handling and transfer-system for the automatic handling,re-orienting, and grouping of loaded six-sided cartons, whereby saidcartons may be changed from a first condition of single file positionalmovement in which they are supported with corresponding sides undermostand horizontally disposed to a second condition of positional movementin which they are disposed in stacks of two or more with saidcorresponding sides being then vertically disposed and co-planar, saidsystem comprising a first conveyor having a horizontally disposedportion, a second conveyor having a horizontally disposed portion, saidsecond conveyor portion being disposed at a substantially lower levelthan saaid first conveyor portion, and transfer means for effecting thechange of said cartons from said first condition of positional movementto said second con dition of positional movement, said transfer meanscomprising: means adapted to extend in a lateral direction across thepath oftravel of said cartons on the horizontally disposed portion ofsaid first conveyor to urge said cartons horizontally transversely ofsaid first conveyor portion and for tipping said cartons through a angleto leave said conveyor portion; platform support means disposed at thelevel of said second conveyor portion and positioned to receive saidcartons'as they drop downwardly from said first conveyor portion;vertically disposed chute-defining guide means operable to maintain thecartons in the attitude in which they leave said first conveyor portionand to stack said cartons in vertical alignment on said platform supportmeans; reciprocally movable pusher means mounted for movementtransversely of said platform support means and operable to push a givenplurality of said stacked cartons, including the lowermost carton, offof said platform support means and onto said second conveyor portion;and reciprocally movable carton support means mounted for up and downmovement relative to said platform means operable when moved upwardly tosupport the remainder of said stacked cartons during operation of saidpusher means and operable when moved downwardly to deposit the remainderof said stacked cartons on said platform support means.

2. A handling and transfer system for the handling, re-mienting, andgrouping of loadedcartons, whereby said cartons may be changed from afirst condition of movement as separated units to a second condition ofmovement as groups of stacked units, said'system comprising a firstconveyor, a second conveyor, the latter being disposed at asubstantially lower level than the former, and transfer means foreffecting transfer of said cartons from said first condition to saidsecond condition of movement, said transfer means comprising: meansadapted to extcnd'in a lateral direction across the path of travelvoftsaid cartons on said first conveyor to move said cartons off of saidfirst conveyor; platform support means disposed adjacent said secondconveyor and positioned to receive said cartons as they drop downwardlyfrom said first conveyor chute-defining guide means operable to guidesaid cartons between conveyor levels and to stack said cartons on saidplatform supportmeans; -reciprocallymovable pusher means mounted formovement transversely of said platform means and operable to move agiven plurality of said stacked cartons, including the lowermostcartomofi of said platform support means andonto said second conveyor;and reciprocally movable carton support means mounted for up and downmove ment relative to said platform means operable when- UNITED STATESPATENTS 2,571,576 Hopkins'etal. Oct. 16, 1951' 2,576,366 Smith Nov. 27,1951 20 2,586,172

Murphy Feb. 19, 195.2

